The present invention relates to card edge connectors, and more particularly, to a card edge connector mounted on a mother board that freely loads and unloads a daughter board.
Card edge connectors, such as those commonly used in personal computers, are mounted on a mother board and freely load and unload a daughter board such as a single inline memory module (SIMM) or double inline memory module (DIMM). An example of one such card edge connector is disclosed in Japanese Patent Laid Open No. 2000-208183 A and is shown in FIGS. 8A through 8C. FIG. 8A shows a card edge connector 101 comprising an insulating housing 110 mounted on a mother board A. The housing 110 has a daughter board receiving recess 111 extending in the longitudinal direction, and a plurality of contacts (not shown) mounted in two upper and lower arrays along the longitudinal direction of the housing 110 that attach to the mother board A. After a daughter board B has been inserted at a first angle into the daughter board receiving recess 111, shown in FIG. 8A, it is pivoted into a second angle, shown in FIG. 8B. The daughter board B is held in place at the second angle by a pair of metal latch members 120 located at both ends of the housing 110 in the longitudinal direction.
Each latch member 120 is formed by stamping and forming a metal plate, and includes a press fit plate portion 121 and a daughter board holding portion 122. Shown in FIG. 8C, the press fit plate portion 121 is press-fitted into a latch receiving recess 112 formed at the ends of the housing 110 in the longitudinal direction and is provided with an anti-overstress piece 123 extending forward from its front end. The anti-overstress piece 123 is provided with a fixing portion 124 bent inward from the bottom end thereof. The fixing portion 124 is soldered onto the mother board A, thereby fixing the latch member 120 to the mother board A.
The daughter board holding portion 122 comprises a plate portion 122a, a hook portion 122b, and a daughter board latching piece 122c. The plate portion 122a is bent substantially forward in the shape of a xe2x80x9cUxe2x80x9d from the back end of the press fit plate portion 121. The hook portion 122b is in the shape of a hook and is located forward from the plate portion 122a and projects inward. The daughter board latching piece 122c is bent inward from the top end of the plate portion 122a. When the daughter board B is inserted into the daughter board receiving recess 111 and is pivoted from the first angle to the second angle, the elasticity of the plate portion 122a temporarily causes the daughter board latching piece 122c to shift outward. When it returns to its original position, the daughter board latching piece 122c makes contact with the upper surface of the edge of the daughter board B to fix it in position. The hook portion 122b enters the notch (not shown) formed in the edge of the daughter board B, further preventing the daughter board B from slipping off the card edge connector 101 when the daughter board B is positioned at the second angle.
Several problems, however, are associated with the card edge connector 101. In the card edge connector 101, the fixing portion 124 that is soldered to the mother board A is bent from the anti-overstress piece 123 that is integrally formed with the other portions comprising the latch member 120. Thus, if the mother board A is warped, the warp of the mother board A can not be absorbed by the fixing portion 124 when it is soldered to the mother board A. As a result, the card edge connector 101, including the latch member 120, can not be properly soldered to the motherboard A if the warp is larger than a predetermined range, even though the coplanarity of the entire connector assembly is within the predetermined range.
In an effort to overcome this problem, devices such as Japanese Utility Model Laid Open No. 5-23429 U, shown in FIGS. 9A through 9C, have been developed. FIG. 9A shows a surface mount type connector 201 mounted on the surface of a circuit board (not shown). The connector 201 comprises an insulating housing 210 and a plurality of contacts 220. The contacts 220 are attached to the housing 210 and have a solder connection portion 221 for attachment to the circuit board. Slots 211 penetrate in the vertical direction and are formed at both ends of the housing 210 in the longitudinal direction. Both sides of the slots 211 have shoulders 212. A metal peg 230 in the shape of an xe2x80x9cLxe2x80x9d and having a slit 232 and barbs 231 at both edges is attached within the slots 211. The metal peg is movable in a predetermined range in the vertical direction. The bottom surface of the peg 230 is soldered to the circuit board to reinforce the connection between the circuit board and the connector 201. The peg 230 is inserted downward into the slot 211 and between the shoulders 212. The upward movement of the peg 230 is thereby limited by the cooperation between the barbs 231 and the shoulders 212. The downward movement of the peg 230 is limited by the cooperation between the upper edge of the slit 232 and a projection 213 projecting from the housing 210 to the slot 211.
Because the peg 230 is movable in the vertical direction with respect to the housing 210 within a predetermined range, the peg 230 is also movable in the vertical direction with respect to the solder connection portion 221 of the contact 220 within a predetermined range. Therefore, when the contact 220 and the peg 230 are soldered to the circuit board, any warping of the circuit board can be absorbed. However, since the metal peg 230 is directly mounted in the slot 211, the barbs 231 on the peg 230 can chip the sides of the slot 211 when the peg 230 is mounted. When the sides of the slot 211 are chipped, the peg 230 can become displaced within the slot 211.
In view of the above-mentioned problems, it is therefore desirable to develop a card edge connector that is capable of absorbing the warp of a mother board when the entire connector, including the fixing member, is soldered to the mother board. It is further desirable to develop a card edge connector where the mother board fixing member is protected from displacement from the latch body.
This invention relates to a card edge connector comprising an insulating housing mounted on a mother board and a latch member. The latch member comprises a latch body having a housing attaching portion attached to the housing and a daughter board holding portion for holding a daughter board. The fixing member is separated from the latch body and is attached to the mother board. The fixing member is mounted on a tab portion formed from the latch body that is moveable in a predetermined range in the vertical direction.